diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2016-08-17 19:20:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-31 17:13:29 +0300 |
| commit | c072e113b8fbd6b2bf325e92379a0da6dea619b3 (patch) | |
| tree | 79c32942e7fec113c9e691544d35afa5a29d282a /drivers/dma/dw | |
| parent | 9217a5bf66061c392e461255c5d9d41aac136e58 (diff) | |
| download | linux-c072e113b8fbd6b2bf325e92379a0da6dea619b3.tar.xz | |
dmaengine: dw: set polarity of handshake interface
Intel Quark UART uses DesignWare DMA IP. Though the DMA IP is connected in such
way that handshake interface uses inverted polarity. We have to provide a
possibility to set this in the DMA driver when configuring a channel.
Introduce a new member of custom slave configuration called 'hs_polarity' and
set active low polarity in case this value is 'true'.
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/dma/dw')
| -rw-r--r-- | drivers/dma/dw/core.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 81b06dfd7e06..80e74216cd56 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -143,6 +143,7 @@ static void dwc_initialize(struct dw_dma_chan *dwc) struct dw_dma *dw = to_dw_dma(dwc->chan.device); u32 cfghi = DWC_CFGH_FIFO_MODE; u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority); + bool hs_polarity = dwc->dws.hs_polarity; if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags)) return; @@ -150,6 +151,9 @@ static void dwc_initialize(struct dw_dma_chan *dwc) cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id); cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id); + /* Set polarity of handshake interface */ + cfglo |= hs_polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0; + channel_writel(dwc, CFG_LO, cfglo); channel_writel(dwc, CFG_HI, cfghi); |